Students at Archbishop Moeller High School have been dismissed after a brief lockdown, the school said in a release.A text message sent just after 1:30 p.m. Thursday alerted parents that Moeller was on lockdown due to an "active threat." Police gave the school the all-clear shortly after 2 p.m.In their release, Moeller officials said the school received a threat and staff immediately put the school on lockdown while Sycamore Township police worked to secure the building. After around 45 minutes, students were dismissed."There was never an active shooter in the building," the release said.